feat: add support for removing thinking tags from input text in BeanOutputConverter

Signed-off-by: liugddx <liugddx@gmail.com>

Author: liugddx

spring-ai-model/src/main/java/org/springframework/ai/converter/BeanOutputConverter.java

@@ -169,6 +169,10 @@ public T convert(@NonNull String text) {
 			// Remove leading and trailing whitespace
 			text = text.trim();
 
+			// Remove thinking tags (e.g., from Amazon Nova models)
+			// These tags can appear at the beginning of the response
+			text = text.replaceAll("(?s)<thinking>.*?</thinking>\\s*", "");
+
 			// Check for and remove triple backticks and "json" identifier
 			if (text.startsWith("```") && text.endsWith("```")) {
 				// Remove the first line if it contains "```json"

spring-ai-model/src/test/java/org/springframework/ai/converter/BeanOutputConverterTest.java

@@ -238,6 +238,49 @@ void convertTypeReferenceArrayWithJsonAnnotations() {
 			assertThat(testClass.get(0).getSomeString()).isEqualTo("some value");
 		}
 
+		@Test
+		void convertWithThinkingTags() {
+			var converter = new BeanOutputConverter<>(TestClass.class);
+			String textWithThinkingTags = "<thinking>This is my reasoning process...</thinking>{ \"someString\": \"some value\" }";
+			var testClass = converter.convert(textWithThinkingTags);
+			assertThat(testClass.getSomeString()).isEqualTo("some value");
+		}
+
+		@Test
+		void convertWithThinkingTagsMultiline() {
+			var converter = new BeanOutputConverter<>(TestClass.class);
+			String textWithThinkingTags = """
+				<thinking>
+				This is my reasoning process
+				spanning multiple lines
+				</thinking>
+				{ "someString": "some value" }
+				""";
+			var testClass = converter.convert(textWithThinkingTags);
+			assertThat(testClass.getSomeString()).isEqualTo("some value");
+		}
+
+		@Test
+		void convertWithThinkingTagsAndMarkdownCodeBlock() {
+			var converter = new BeanOutputConverter<>(TestClass.class);
+			String textWithThinkingTags = """
+				<thinking>This is my reasoning process...</thinking>
+				```json
+				{ "someString": "some value" }
+				```
+				""";
+			var testClass = converter.convert(textWithThinkingTags);
+			assertThat(testClass.getSomeString()).isEqualTo("some value");
+		}
+
+		@Test
+		void convertWithMultipleThinkingTags() {
+			var converter = new BeanOutputConverter<>(TestClass.class);
+			String textWithThinkingTags = "<thinking>First thought</thinking><thinking>Second thought</thinking>{ \"someString\": \"some value\" }";
+			var testClass = converter.convert(textWithThinkingTags);
+			assertThat(testClass.getSomeString()).isEqualTo("some value");
+		}
+
 	}
 
 	// @checkstyle:off RegexpSinglelineJavaCheck